The article has been updated with information about a possible Lion release in the UK.

We are receiving multiple reports of Apple telling developers that iTunes Connect will be undergoing scheduled maintenance today from 9am to 4pm Pacific Time. The iTunes Connect site is where content providers upload and manage their itunes submissions such as songs, movies, apps and more. Apple is advising developers not to make price changes during the blackout because that will cause apps to become unavailable for purchase. Additionally, regional App Stores in Mexico, UK, Australia, Switzerland, Norway or Japan may not sell apps at all during the maintenance period, Apple writes. The heads-up signals the imminent release of OS X Lion tomorrow, as previously rumored. Some people also reported reporting having difficulties entering the Mac App Store, but this issue appears to have been resolved by now.

We are also expecting some new Mac minis, the updated white MacBook and, of course, the refreshed MacBook Airs, with Mac Pros to follow later this month. As you know, OS X Lion will be distributed exclusively via the Mac App Store as a digital download weighing in at just under four gigabytes. If anything, the digital-only release will test the capabilities of Apple’s latest data center in North Carolina. Full contents of Apple’s email is right after the break.

iTunes Connect will be undergoing scheduled maintenance on Wednesday, July 13 from 9 a.m. to 4 p.m. PDT.

During this time, iTunes Connect will still be available. However, pricing changes made between 9 a.m. and 4 p.m. PDT will cause the app to become unavailable for purchase until maintenance is complete, at which point the app will become available at the new price. To avoid interruptions to the availability of your apps, do not make price changes during this time.

Lastly, customers may not be able to purchase apps in the Mexico, U.K., Australia, Switzerland, Japan or Norway storefronts during the scheduled maintenance.